1. Field of the Invention
This invention relates to sealing means for use on screws.
2. Prior Art
It is often necessary to retain lubricants between a screw and a nut, particularly where the screw and nut are subjected to large loads in hostile environments. Such an application is the recirculating ball screws used to raise and lower the flaps of many commerical jet aircraft. In many of these applications a screw seal is coupled at the opposite ends of the nut for retaining lubricants between the nut and screw.
In applicant's prior screw seal disclosed in U.S. Pat. No. 3,669,460 a screw seal carrier which includes a chipping surface, wiping surface, and a sealing member is employed. The chipping surface is used to chip away foreign matter on the screw. The wiping surface wipes the screw of lubricants and the sealing member is employed to form the seal between the nut and screw. While this screw functions satisfactorily, some repeatability problems have been encountered with its use. These problems are caused, in part, by dimensional variations in the screws.
The present disclosure describes an improved screw seal, and more particularly a screw seal with an improved wiper. As will be described in more detal, the wiper includes a sealing means and a drain groove to direct lubricants between the nut and screw.